Ratches

The Ratches are an unlikely hybrid of cockroaches and rats created by the questionable housekeeping practices at "O'Jacks" fast food place. They can fly and the bug spray does nothing. Mankind has met their inevitable doom.

First appearance (mentioned) [http://shotgunshuffle.com/did-i-mention-they-also-fly/ "Did I mention they also fly?" ] First "real" appearance "Ratches"

While not employees as such, their impact on the lives of those who worked at the store where they were created can't be underestimated. See, "the day we were all fired."